New recyclable biodiesel catalyst developed

Posted Aug. 25, 2010

Researchers from Down to Earth Energy, a biodiesel research and production facility in Monroe, Ga., and the University of Georgia have developed a new, recyclable biodiesel catalyst. "Most current production methods use concentrated sulfuric acid and caustic methoxides as catalysts in these reactions," Tyson Johnson, Down to Earth Energy CFO, said. "The problem that all biodiesel producers know too well is that using these liquid acids and caustics creates a whole host of problems that have to be dealt with in post-processing."

The answer to all of those problems, Johnson told Biodiesel Magazine, is to reuse the catalyst by keeping it in one place. "We've taken effective catalytic functional groups and immobilized them on a solid substrate." The catalysts remain in a fixed column, allowing for further use in future reactions. "We've got a two-stage heterogeneous reaction with recoverable and reusable catalysts," Johnson said, adding that the process drastically cuts down on the waste effluents that result from conventional production methods.

The catalysts are made from natural materials that are readily available. Starting with woody biomass, Johnson said the team has developed an economical generation method for the reusable catalysts. "After generation, what goes into the reactor looks and feels a lot like charcoal." The goal he also said, "is to give every biodiesel producer no matter how large or small an affordable solid catalyst that can be easily integrated into any process-batch or continuous."

Because the process does not require the addition of acids and caustics or the neutralization of those, Johnson said, the glycerin product will be largely free of soaps, salts and will be pH neutral. The recycled catalysts however, act as an adsorbent/catalyst, allowing some front-end impurities to adsorb onto the catalyst surface. But, Johnson said, there is a trade-off. "The dirtier the oil going in, the shorter the life of the catalyst, the shorter the amount of time before regeneration is necessary."

While the team continues working on the process, producers interested in implementing the catalyst will have to wait. "Right now we are focused on giving this technology in its current form the best chance we can and also in developing the relationships that will help get these catalysts to market." Some of those relationships have already paid off. Jim Kastner and Dan Geller, who are with University of Georgia's Agriculture Engineering Department, have helped the partnership between Down to Earth Energy and the school grow. "The initial idea for the project came from Jim and Dan, both of whom have been working with biochar and pyrolysis technologies for some time now," Johnson said. Along with Larry Keith, chemist for Down to Earth Energy, Johnson said the project has so far been a success.